Idea: Why not do as they did in the catacombs? (or similar burial sites)
"Bury" the person, then later, after the body has gone down to bones, collect the bones and place them in a smaller box in another location. The family could have a set spot for the temporary burial of their family members, then after time, the bones of their ancestors would be moved to a family (or public) burial site.
I'd think both sides kind of win... No cremation, and land isn't taken up as easily/quickly. Not to mention just like many cremation sites, the bones could be placed in a spot that is vertical as well as horizontal (that is, either up, down, or to any horizontal sides)...
If that makes any sense.